@model ActivityViewModel<NotifyTask>
@using OrchardCore.DisplayManagement.Notify
@{
    string className = "info-circle";

    switch (Model.Activity.NotificationType)
    {
        case NotifyType.Error:
            className = "exclamation-circle";
            break;
        case NotifyType.Success:
            className = "check-circle";
            break;
        case NotifyType.Warning:
            className = "warning";
            break;
    }
}
<header>
    <h4><i class="fa fa-@className"></i>@Model.Activity.GetTitleOrDefault(() => T["{0} Notification", Model.Activity.NotificationType])</h4>
</header>
<em>&quot;@Model.Activity.Message&quot;</em>